Concentrating table for mineral recovery



Aug. 30, 1966 J. STEPHAN CONCENTRATING TABLE FOR MINERAL RECOVERY 2Sheets-Sheet 1 Filed May 7, 1963 NFU INVENTOR. STEP/MN I ArraeA/Evs.

Aug. 30, 1966 J. STEPHAN 3,269,53g

CONCENTRATING TABLE FOR MINERAL RECOVERY Filed May 7, 1963 2Sheets-Sheet 2 INVENTOR. ZIOSEPH $7'EPHA7A/ 147' TGEWE Y5- United StatesPatent 3,269,538 CQNQENTRATENG TABLE MINERAL RECOVERY doseph Stephan,fiahersiield, alili (P263. Box 695, Apache function, Ariz. aszza FittedMay 7, 1963, Ser. No. 278,679 iii-aims. (U. 29-d41) This inventionrelates generally to apparatus for recovery of minerals, and morespecifically is directed to a novel table having a downwardly inclinedbed of unique construction, and means for cyclically imparting to thebed a vibratory reciprocating longitudinal movement of small magnitudebut of relatively high frequency, of the order of 750 cycles per minute.The apparatus is applicable for use with milled ore, placer material andcontinuous ejection of concentrates.

In accordance with a preferred embodiment of the invention hereinafterdescribed and illustrated in detail, there is provided a horizontal baseof generally rectangular rigid construction carried by a supportingframework adapted to rest on the ground or other surface. Above the baseand substantially coextensive therewith is a horizontally disposedcradle movably supported by the base by means such as link armspermitting rapid cyclic vibratory longitudinal movement of the cradlerelative to the base. A generally rectangular pan frame, substantiallycoextensive with the cradle or somewhat larger than the latter, ispivotally connected at its one end to the cradle about a horizontal axisand means are provided for elevating its other end at a selectivelyadjustable distance above the cradle, whereby the pan frame can bepositioned at any desired inclination to the horizontal within a rangeof or thereabouts. However, conventional operation of the apparatus inaccordance with the invention will more frequently involve an upwardinclination of the pan frame from its pivotal connection with the cradleof between about 8 and 15.

The pan frame includes a rectangular bed having side walls and thedistal end wall extending upwardly fro-m the bed a suitable distancesuch as 6 or 8 inches. The end wall at the pivoted end of the bed may belower extending upwardly from the bed only two or three inches andconstituting an overflow flange for tailings and other waste. At thedistal end of the pan frame, where material to be treated is introduced,water supply means are provided. The means for imparting vibratorymotion to the cradle and thus to the pan frame desirably include arotatable cam journaled to the base and having a surface which is aninterrupted portion of a spiral bearing against a cylindrical roller orthe like rotatably journaled on the cradle. Resilient means are providedfor strongly biasing the cradle roller into contact with the spiral camsurface, and the interruption in the latter imparts a cyclic jarringmovement to the cradle.

The novel configuration of the pan frame bed, downwardly from thewashing means at the distal end, includes a series of elements extendinggenerally transversely of the bed and having a saw tooth upper contouras seen in vertical section. Each element is desirably upwardly concavethroughout its length, the portion of the element midway between the panframe side walls being slightly lower than the ends of the elementsadjacent said side walls. The vertical surfaces of the saw tooth contourface downstream, and the rapid jar or jolt of the cradle during itsmovement cycle displaces the vertical surfaces in the upstream directionwhereby the higher specific gravity items tend to remain close to thevertical faces while the lower specific gravity waste tends to movedownwardly along the length of the bed.

The elements forming the bed are slightly inclined to 'ice aperpendicular to the length of the pan frame, so that concentrates tendto move toward the ends of the elements further downstream. The elementsat those ends stop one half inch or so short of the pan frame side wall,exposing the underlying smooth surface of the bed floor and constitutinga longitudinal channel along the bottom of said side wall. Means areprovided for selectively blocking said channel, desirably in the form ofbars fitting snugly in the channel and extending upwardly well above thebed elements.

At one corner of the lower end of the bed is an outlet through the bedfloor for discharging the concentrates into a suitable receptacle, and adarn extends across the approach to the outlet to prevent any of thewaste material from entering the outlet with the concentrates. At theother corner of the lower end of the bed there may be provided anotheroutlet in the bed floor, preferably smaller than the first mentionedoutlet, for receiving concentrates of intermediate specific gravity anddischarging the same into a suitable container or receptacle benea-ththe bed.

In operation, the present table virtually eliminates the packing of mud,clay or slime, as has been true with prior concentrating tables, andoperates with a minimum of water.

Accordingly it is a principal object of the present invention to providea novel vibrating table for concentrating minerals, either milled ore orplacer. Other objects are to provide in such a table a bed having anupper contour, as seen in longitudinal vertical section, of a series ofsaw teeth having gently rising upper faces and sharply falling,downwardly directed, vertical faces; to provide such a bed made up of aseries of elements extending generally transversely of the direction ofmaterial movement; to provide, in such a bed, a smooth narrow channelalong one side of the bed, and removable means for selectively blockingthe channel; to provide elements forming such a bed wherein the elementsare concave upwardly throughout their extent; to provide in such a tablemeans for imparting a periodic sharp jar or jolt to the bed in anupstream direction; and for allied and additional objects and purposesas will become clear from the following description of a preferredembodiment of the invention taken in connection with the accompanyingdrawings, in which:

FIG. 1 is a side elevational view of a concentrating table in accordancewith the present invention, the bed being shown elevated by an angle ofa few degrees.

FIG. 2 is a plan view of the bed of the device of FIG. 1.

FIG. 3 is a fragmentary sectional view taken on the arrows III-III ofFIG. 2.

FIG. 4 is a transverse sectional view of one of the elements of the bedtaken on arrows IVIV of FIG. 2.

FIG. 5 is a fragmentary view taken on arrows V--V of FIG. 1 showing apreferred form of the vibratory motion imparting means in accordancewith the invention.

FIG. 6 is a sectional view taken on the arrows VI-VI of FIG. 5 showingthe cam having an interrupted spiral surflace and the cylindrical rollerin rolling contact therewit Referring now in detail to the drawings, aconcentrating table for mineral recovery in accordance with the presentinvention is seen in FIG. 1 and includes a generally horizontallydisposed rectangular base indicated generally at 8 and includingparallel side members It and 12 (see FIG. 5) joined by transverse endmembers 11 and 13. The base is supported by a suitable substructureincluding upright members 7 of adequate strength and rigidity. Overlyingthe base and generally coextensive therewith is a rectangular cradleindicated generally at 15, having a pair of laterally spacedlongitudinal side members 16 and 155 (see FIG. joined by transverse endmembers 17 and 19. Cradle is supported by the base for limitedlongitudinal movement relative to the base, the support means in thepresent illustrative form of the invention including generallyvertically disposed links, of which two are seen in FIG. 1 and areindicated generally at 20 and 22. It will be understood that a similarpair of links are located on the opposite side of the base and cradle,there being one link joining each corresponding corner of the cradle andbase. Link 211 is pivotally attached at its upper end to a stub shaft 23carried by the cradle longitudinal side member 16 and extendingoutwardly therefrom, while the lower end of link 20 is pivotallyconnected to a stub shaft 24 carried by the base longitudinal sidemember 10 and extending outwardly therefrom. Link 22 is similarlypivotally connected at its upper end to a stub shaft 25 carried by andprojecting outwardly from the cradle longitudinal side member 16, and ispivotally connected at its lower end to a stub shaft 26 carried by andextending outwardly from the base longitudinal side member 10.

Means are provided for biasing the cradle 15 rightwardly as seen in FIG.1 relative to the base, and desirably such means are adjustable as tobiasing force. The present illustrative form of the invention includes alaterally spaced pair of such means, one being indicated generally at 28and including a heavy coil spring 30 abutting at its left end an angleplate 32 fixed to the base side member 10 and at its right end bearingagainst a collar 34 carried on the shank of a bolt 36 threaded throughan aperture of a downwardly depending flange fixed to the cradle sidemember 16, with nuts 39 and 4t) threaded on the shank of bolt 36 andjammable against the flange 38 to lock the bolt in a selected position.

Means are provided for imparting a cyclical reciprocating or vibratorymotion to the cradle 15 relative to the base. A preferred form of suchmeans is best seen in FIGS. 5 and 6. As there appears, a shaft 4-0 isjournaled in the cradle side members 16 and 18, and the shaft carriesthereon a pair of cylindrical discs 42 and 44 spaced axially of theshaft, relatively close to the respective cradle side members 16 and 18.A second shaft indicated generally at similarly extends transversely ofthe table, but is journaled in pillow blocks or the like 62 and 64 fixedto the frame longitudinal members 111 and 12 respectively. The shaft 60extends through enlarged openings 71 and 72 in the cradle side members16 and 18, and does not touch either of said latter named members duringany permissible excursion of the cradle.

A pan table indicated generally at is pivotally connected about ahorizontal transverse axis 72 to one end of cradle 15. At the oppositeor distal end, means indicated generally at 74 are provided forelevating such distal end of the pan table to a desired height, in orderto give the pan table the optimum inclination for the particularmaterial being treated. In the present embodiment such means include apair of laterally spaced arcuate arms fixed to the pan table adjacentits distal end and extending generally downwardly therefrom, one of sucharms being indicated at 75 and provided with a series of spaced teeth 76separated by grooves 77. A locking crossbar 78 may be received in aselected pair of grooves, the crossbar resting on the cradle members 16and 18.

Means are provided for rotating shaft 611 as through a belt and sheaveindicated generally at 80, and the shaft carries fixed thereon a pair ofcam members 82 and 34, adjacent the cradle side members 16 and 18respectively. The outer surfaces of cam members 82 and 84 are in contactwith the respective cylindrical discs 42 and 44 on shaft 40, the partsbeing biased into contact by the spring means 28 heretofore described.

As best seen in FIG. 6, the outer surface of the cam member 82 (84 beingidentical thereto) consists of a spiral interrupted by a radial shoulder92 extending between the minimum radius of the spiral and the maximumradius thereof. The power means applied to the shaft 60, as throughsheave 80, is adapted to rotate shaft 60 clockwise as seen in FIG. 6.Keeping in mind that the axis of the shaft 60 is fixed relative to theframe of the table, it will be understood that rotation of the earns 82and 84 caused by rotation of shaft 64) causes a relatively slow leftwardmovement of discs 42 and 44, and thereby of shaft 41 and cradle 15,followed by a sharp rightward jarring movement when the shoulder 92 ofcam 82 passes disc 42. Such rapid jarring or jolting movement resultsfrom the force of the resilient means 28 at the other end of the tableheretofore described. Buffer means may be provided to soften thesharpness of such movement to the degree desired, an illustrative formof such means being indicated generally at 91 and including a coilspring 93 biasing the cradle leftwardly as seen in the drawing by anadjustable force controlled by bolt 94.

With reference now to FIGS. 2, 3 and 4, the bed of pan table 71) ispreferably made up of a number of adjacent strip elements extending fromone side wall 11M), and terminating close to the other side wall 1112,thereby leaving a relatively smooth surface channel along said side wall102. Each strip element is fixed to the pan table floor 1116 as byrivets 111 or the like and includes a generally vertical surface 112facing toward the lower pivoted end of the pan table, as well as a.smooth inclined surface 114 upstream of said vertical surface. Duringvibratory movement of the pan table as previously described, at a cyclicrate in the neighborhood of 750 cycles per minute, the particles oflower specific gravity tend to move downstream of the pan table, whilethe valuable concentrates of relatively high specific gravity tend toremain on the surface 114 of one element, adjacent the vertical surface112 of the upstream element. Such heavy concentrates tend also to movetoward side wall 102, because the strip elements 111 are inclined at asmall anglepreferably between about 4 and about 12to the perpendicularto the axis of movement of pan table 71). It will be noted that suchinclination is downwardly of the inclined pan table from side wall 1%toward side wall 102, and it will be further noted, as seen in FIG. 4,that the strip elements may be slightly higher at their ends adjacentside wall 1% than at their opposite ends, adjacent side wall 102.

FIG. 4 also shows the slight upward concavity of the upper surfaces ofstrip elements 110 throughout their length, thus tending to channel themain downward fiow of material generally centrally of the width of thepan table under the influence of water 115 sprayed from the water supplymeans indicated generally at 116 in FIGS. 1 and 2 mounted above thedistal end portion of the pan table.

As previously mentioned, strip elements 110 do not extend to side wall1112, but are spaced therefrom, leaving a smooth surface channel 197immediately adjacent side wall 1112. In the upper portion of the table,immediately downstream of water source 116, the channel 1117 is blockedby a removable closure bar 118 of metal or other suitable materialextending across the ends of the upper few strip elements, and a secondand preferably longer such closure bar 119 blocks channel 1117 acrossthe ends of most of the remaining downstream strip elements, as seen inFIG. 2. Each closure bar is held in place by suitable fastening meanssuch as one or more bolts 120 extending through openings in side wall102. An upstanding diverter strip 122 may be fixedly mounted on thefloor 106 as by welding, extending angularly downwardly and inwardlyfrom the lower portion of closure bar 118, and a dam 124, fixed to floor1% and projecting upwardly therefrom, may extend at a generally similarangle from the lower portion of closure bar 119 to lower end wall 103preventing tailings and other waste material from access to opening 104leading downwardly to outlet 105 for the concentrates. Thus fixed strip122 and dam 124 assist in channeling the waste material over the endwall 108, which is desirably of lower height than side walls 100 and 102of the pan table.

In operation, a supply of material to be classified such as milled ore,placer or the like is placed upon the upper portion of the pan tableunder water source 116. Flow downwardly along the bed across thesuccessive saw tooth surfaces of strip elements 110 will result from thevibratory motion imparted to the cradle and pan table as previouslydescribed. The unusual characteristic of such motion, in combinationwith the saw tooth surface of the bed, creates extremely effectiveclassification by specific gravity of the particles of material beingtreated. The particles of relatively high specific gravity including thevaluable material, tend to stay very close to the vertical surfaces ofthe successive saw teeth, While the particles of low specific gravityare washed over the successive saw teeth generally downwardly of thebed. Moreover, 'because of the slight inclination of the verticalsurfaces of the saw teeth relative to the perpendicular to thelongitudinal axis of the bed, the particles of high specific gravity areurged toward the side wall 102, and are prevented from entering thechannel 107 adjacent said side wall by reason of the presence of theclosure bars heretofore described. Thus, after a desired run has beencompleted, with the tailings and other wastes going over the lower endof the bed, the bars may be removed, whereby to permit the concentratesadjacent said bars to flow downwardly in the channel 107 to the opening104 at the lower end of the table, and through the outlet 105 into anydesired collecting vessel mounted therebelow.

Modifications and changes from the preferred form of the inventionheretofore described and illustrated are Within my contemplation, andall such modifications and changes not departing from the spirit of theinvention are intended to be embraced within the scope of the appendedclaims.

I claim:

1. A concentrating table for mineral recovery comprising:

a pan table having a generally rectangular floor and a wall extendingupwardly from the floor along one side thereof;

a bed on said floor spaced from said wall to define a channel extendinglongitudinally of the table floor adjacent said wall, said bed providinga series of surfaces substantially perpendicular to the table floor,extending generally transversely thereof and facing one end of the tablefloor, said surfaces being spaced apart longitudinally of the tablefioor by smooth surfaces slightly inclined relative to the table floorand extending between the bottom of each of said perpendicular surfacesand the top of the perpendicular surface next closer to said table floorend;

said perpendicular surfaces being inclined slightly to the perpendicularto the longitudinal table axis whereby the ends of said perpendicularsurfaces adjacent said channel are closer to said one table floor endthan are opposite ends thereof, said one table floor end beinghorizontal;

means for supporting said table with its floor inclined at a selectedangle upwardly from said one table floor end;

and means for imparting longitudinal vibratory motion to said table. 2.The invention as stated in claim 1 including removable closure meansreceivable in said channel for selectively blocking the same.

3. The invention as stated in claim 1 wherein the end of each of saidsmooth surfaces distant from said channel is spaced farther above thetable floor than is the end adjacent the channel.

4. The invention as stated in claim 1 wherein said motion impartingmeans includes means for moving the table slowly toward said end andthen rapidly away from said end.

5. In a concentrating table for mineral recovery, in combination:

a pan table including a flat floor and an elongated bed thereon, andhaving upstanding side and end walls;

cradle means for supporting said pan table, the pan table beingpivotally attached to the cradle adjacent one end thereof for swingingabout a horizontal axis, and including selectively adjustable meansadjacent the other end of the pan table for positioning said other endat a desired height above the corresponding end of the cradle means;

said bed having, throughout at least the lower portion thereof, a crosssectional shape, as viewed in longitudinal vertical section, of sawteeth with substantially vertical surfaces facing the pivoted end of thepan table, said bed being made up of a plurality of generallytransversely extending strip elements fixed to the pan table andextending from the abutting relation with one side wall of the pan tableto a point spaced inwardly from the other side wall, thereby forming achannel adjacent said other side wall, and the upper surface of eachelement being concave upwardly, each element, at its end adjacent thechannel, extending upwardly from the floor by a smaller distance than atthe other end of the element;

and means for imparting to the cradle and thereby to the pan table acyclical vibratory reciprocating motion including a relatively slowmovement of the pan table and cradle in the direction of said pivotedend and a sudden movement in the opposite direction.

References Cited by the Examiner UNITED STATES PATENTS 163,104 5/1875Pomeroy 209---437 2,496,025 1/ 1950 Stephen 209-441 3,108,950 10/1963Buckley 209-466 HARRY B. THORNTON, Primary Examiner.

FRANK W. LUTTER, Examiner.

L. H. EATHERTON, Assistant Examiner.

1. A CONCENTRATION TABLE FOR MINERAL RECOVERY COMPRISING: A PAN TABLEHAVING A GENERALLY RECTANGULAR FLOOR AND A WALL EXTENDING UPWARDLY FROMTHE FLOOR ALONG ONE SIDE THEREOF; A BED ON SAID FLOOR SPACED FROM SAIDWALL TO DEFINE A CHANNEL EXTENDING LONGITUDINALLY OF THE TABLE FLOORADJACENT SAID WALL, SAID BED PROVIDING A SERIES OF SURFACESSUBSTANTIALLY PERPENDICULAR TO THE TABLE FLOOR, EXTENDING GENERALLYTRANSVESELY THEREOF AND FACING ONE END OF THE TABLE FLOOR, SAID SURFACESBEING SPACED APART LONGITUDINALLY OF THE TABLE FLOOR BY SMOOTH SURFACESSLIGHTLY INCLINED RELATIVE TO THE TABLE FLOOR AND EXTENDING BETWEEN THEBOTTOM OF EACH OF SAID PERPENDICULAR SURFACES AND THE TOP OF THEPERPENDICULAR SURFACE NEXT CLOSURE TO SAID TABLE FLOOR END; SAIDPERPENDICULAR SURFACES BEING INCLINED SLIGHTLY TO THE PERPENDICULAR TOTHE LONGITUDINAL TABLE AXIS